1. Field of the Invention
The present invention relates to a process for producing a fluoroelastomer, more particularly, it relates to a process for producing a novel fluoroelastomer of propylene-tetrafluoroethylene-glycidyl vinyl ether terpolymer.
2. Description of Prior Art
It has been known that propylene-tetrafluoroethylene copolymers are excellent fluoroelastomers. (Japanese Patent Publication No. 24199/1968; U.S. Pat. No. 3,467,635 and B. Pat. No. 1,284,247)
Thus, the fluoroelastomers of propylene-tetrafluoroethylene copolymer, have excellent heat resistance and chemical resistance whereas they have inferior vulcanization properties.
In order to improve the vulcanization properties, it has been proposed to incorporate a comonomer into the copolymer for forming crosslinkable parts such as chloroethyl vinyl ether, acrylic acid, tertiary butyl acrylate, and divinyl ether.
According to the study made by the inventors, it has been found that there remain some disadvantages in the vulcanization step of the above-mentioned known ternary systems, such as blistering, insufficient vulcanization rate and necessity of high vulcanization temperature, and that most of their resultant vulcanizates show inferior heat stability to those of the binary systems.